This has been going on since Saturday morning, so today I messaged the plumber. I get luke warm water from the tap, with the occasional bit of hot, but the heating is okay. He came round at midday, he's very good, and said there was a part that had gone, and a part that was almost gone and he'd get prices. The boiler is fairly old, it may not be worth it, and I said I'd rely on his professional judgement, I trust him.

Although I missed the bouldering wall this morning, I was able to get to the art class this afternoon. Two hours solid concentration before a break, and another hour afterwards. No wonder I'm yawning my head off!